Method of identifying iris

ABSTRACT

A method of identifying iris includes: providing incident beams entering an eye locating at a reference position; setting a first, a second and a third reference point for locating the eye at the reference position; forming a first, a second and a third measuring glint by the incident beams after the eye moves from the reference position to a measuring position, and positions of the first, the second and the third measuring glint corresponding to the positions of the first, the second and the third reference point; capturing an eye image including a first, a second, a third measuring glint image and an iris image; comparing the gray scale value with a threshold gray scale value to obtain the positions of the first, the second and the third measuring glint; and calculating a first and a second variation to obtain an resolution variation of the iris image.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 15/588,473, filed on May 5, 2017, and entitled “METHOD OFIDENTIFYING IRIS”, which is a continuation application of U.S.application Ser. No. 14/478,517, filed on Sep. 5, 2014, and entitled“EYE DETECTING DEVICE AND METHODS OF DETECTING PUPIL”, the entirecontents of which are hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to an eye detecting device, in particularan eye detecting device for detecting pupil and identifying iris.

2. Description of Related Art

Currently, the eye detecting device can be used to detect gaze directionor identify iris boundary. Most eye detecting devices detects the eyegaze direction by using the characteristic that the position of pupilchanges with the gaze direction.

Generally, conventional eye detecting device detects the eye gazedirection by using the glint formed by emitting the incident light intothe eye, and the glint is used to be a reference point for locating eye.

Specifically, after capturing eye image, the conventional eye detectingdevice identifies the pupil and glint from the whole cornea image. Inthe process of identifying the pupil, the conventional eye detectingdevice scans whole eye image. The conventional eye detecting deviceanalyzes the gray scale value distribution of whole eye image foridentifying the pupil and glint. The conventional eye detecting devicecan obtain the relative position of the pupil and glint, and thendetermines the gaze direction according to the relative position.

SUMMARY

An exemplary embodiment of the present disclosure illustrates an eyedetecting device which determines the position of the pupil according toat least one glint.

An exemplary embodiment of the present disclosure illustrates a methodof identifying iris includes: providing, by an optical assembly, aplurality of different incident beams entering an eye, the eye locatingat a reference position, wherein the optical assembly includes only onesingle light source and only one light dispersing component, and theonly single light source is configured to generate light entering intothe only one light dispersing component so that the light is dividedinto the plurality of incident beams entering the eye by the lightdispersing component; setting a first reference point, a secondreference point and a third reference point as a mark for locating theeye at the reference position, wherein positions of the first referencepoint, the second reference point and the third reference point arecorresponding to emission positions of the incident beams; forming afirst measuring glint, a second measuring glint, and a third measuringglint near a pupil of the eye by the incident beams after the eye movesfrom the reference position to a measuring position, and a plurality ofpositions of the first measuring glint, the second measuring glint, andthe third measuring glint are corresponding to the positions of thefirst reference point, the second reference point and the thirdreference point; capturing an eye image of the eye including a firstmeasuring glint image, a second measuring glint image, a third measuringglint image, and an iris image; analyzing a gray scale value of the eyeimage by comparing the gray scale value with a threshold gray scalevalue through an arithmetic unit to obtain the positions of the firstmeasuring glint, the second measuring glint, and the third measuringglint; and calculating a first variation of a first line defined by thefirst measuring glint and the second measuring glint with respect to afirst reference line defined by the first reference point and the secondreference point, and calculating a second variation of a second linedefined by the second measuring glint and the third measuring glint withrespect to a second reference line defined by the second reference pointand the third reference point, so as to obtain an resolution variationof the iris image when the eye is located at the measuring position.

An exemplary embodiment of the present disclosure illustrates a methodof detecting pupil which determines the position of the pupil accordingto one glint or plurality of glints.

An exemplary embodiment of the present disclosure illustrates a methodof detecting pupil including providing at least one incident lightentering an eye to form at least one first glint, and the first glint islocated near a pupil of the eye. Capturing a first eye image including aglint image and a pupil image. Analyzing a gray scale value of the firsteye image to obtain the distributions of the first glint. Determining aposition of the pupil of the eye according to the distributions of thefirst glint.

An exemplary embodiment of the present disclosure illustrates a methodof identifying iris which obtains a deformation amount of the iris imageof the eye while the eye moving.

An exemplary embodiment of the present disclosure illustrates a methodof identifying iris including when an eye is located at a referenceposition, providing a plurality of incident lights entering the eye toform a plurality of a first reference point, a second reference pointand a third reference point located near a pupil of the eye as a markfor locating the eye at the reference position, wherein the positions ofthe first reference point, the second reference point and the thirdreference point are corresponding to the emission position of theincident lights. When the eye moves from the reference position to ameasuring position, the incident lights form a first measuring glint, asecond measuring glint, and a third measuring glint near a pupil of theeye. Capturing a eye image of the eye including a first measuring glintimage, a second measuring image, a third measuring glint image, and aniris image. Analyzing a gray scale value of the eye image to obtain thepositions of the first measuring glint, the second measuring, and thethird measuring glint. Calculating a displacement amount of the firstmeasuring glint, the second measuring glint, and the third measuringglint relative to the first reference point, the second reference pointand the third reference point respectively, so as to obtain adeformation amount caused by the iris image of the eye at the measuringposition relative to the iris image of the eye at the referenceposition.

An exemplary embodiment of the present disclosure illustrates a methodof identifying iris which obtains a resolution variation of the irisimage of the eye.

An exemplary embodiment of the present disclosure illustrates a methodof identifying iris including providing a plurality of incident lightsentering the eye. Setting a first reference point, a second referencepoint and a third reference point as a mark for locating the eye at thereference position, wherein the positions of the first reference point,the second reference point and the third reference point arecorresponding to the emission position of the incident lights. Theincident lights form a first measuring glint, a second measuring glint,and a third measuring glint near a pupil of the eye, and a plurality ofpositions of the first measuring glint, the second measuring glint, andthe third measuring glint are corresponding to those positions of thefirst reference point, the second reference point and the thirdreference point. Capturing a eye image of the eye including the firstmeasuring glint image, the second measuring image, the third measuringglint image, and an iris image. Analyzing a gray scale value of the eyeimage to obtain the positions of the first measuring glint, the secondmeasuring glint, and the third measuring glint. Calculating a variationof the distance between the first measuring glint and the secondmeasuring glint with respect to the distance between the first referencepoint and the second reference point, and calculating a variation of thedistance between the second measuring glint and the third measuringglint with respect to the distance between the second reference pointand the third reference point, so as to obtain an resolution variationof an iris image when the eye is located at the measuring position.

In summary, the present disclosure provides eye detecting device,methods of detecting pupil and identifying iris. The eye detectingdevice includes an optical assembly, an image sensor, and an arithmeticunit. The arithmetic unit can analyze the gray scale value distributionof the survey area near the arrangement of the glint in the first eyeimage so as to reduce searching scope of the pupil. Hence, the positionof the pupil can be searched quickly. Therefore, compared withconventional technology, the arithmetic unit does not analyze the grayscale value distribution of whole first eye image for searching scope ofthe pupil.

The present disclosure provides A method of identifying iris includes:providing, by an optical assembly, a plurality of incident beams andforming a plurality of glints reflected by the incident beams; setting afirst reference point, a second reference point and a third referencepoint as a mark for locating the eye at a reference position; forming afirst measuring glint, a second measuring glint, and a third measuringglint near a pupil of the eye by the incident beams after the eye movesfrom the reference position to a measuring position; capturing an eyeimage of the eye including a first measuring glint image, a secondmeasuring glint image, a third measuring glint image, and an iris image;analyzing a gray scale value of the eye image by comparing the grayscale value with a threshold gray scale value through an arithmetic unitto obtain the positions of the first measuring glint, the secondmeasuring glint, and the third measuring glint; calculating a firstvariation of a first line defined by the first measuring glint and thesecond measuring glint with respect to a first reference line defined bythe first reference point and the second reference point, andcalculating a second variation of a second line defined by the secondmeasuring glint and the third measuring glint with respect to a secondreference line defined by the second reference point and the thirdreference point; and calculating an iris image deformation amountaccording to the first variation, the second variation and the thirdvariation. The iris image deformation amount is caused by the iris imageof the eye at the measuring position relative to the iris image of theeye at the reference position.

The arithmetic unit can calculate the major axis and minor axis of thesaid ellipse according to the first variation, the second variation, andthe third variation. Hence, the boundary of the pupil P1 can beestimated so that the boundary of the pupil P1 can be searched quickly.

The present disclosure provides methods of identifying iris. Thearithmetic unit can calculate the major axis and minor axis of the saidellipse according to the first, second, and third variation. Hence, theboundary of the pupil can be estimated so that the boundary of the pupilcan be searched quickly.

The present disclosure provides methods of identifying iris. Thearithmetic unit can calculate the first, second, and third variation.Hence, the boundary of the pupil can be estimated so that the boundaryof the pupil can be searched quickly.

In order to further understand the techniques, means and effects of thepresent disclosure, the following detailed descriptions and appendeddrawings are hereby referred, such that through which, the purposes,features and aspects of the present disclosure can be thoroughly andconcretely appreciated; however, the appended drawings are merelyprovided for reference and illustration, without any intention to beused for limiting the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the present disclosure and, together with thedescription, serve to explain the principles of the present disclosure.

FIG. 1A depicts a side view of the eye detecting device in accordancewith the first embodiment of the present invention.

FIG. 1B is a front view of the eye detecting device shown in FIG. 1A.

FIG. 1C is a function block diagram of the eye detecting device inaccordance with the first embodiment of the present invention.

FIG. 1D depicts a flow diagram of a method of detecting pupil inaccordance with the first exemplary embodiment of the presentdisclosure.

FIG. 2A depicts a side view of the eye detecting device in accordancewith the second embodiment of the present invention.

FIG. 2B is a function block diagram of the eye detecting device inaccordance with the second embodiment of the present invention.

FIG. 2C depicts a flow diagram of a method of detecting pupil inaccordance with the second exemplary embodiment of the presentdisclosure.

FIG. 3A depicts a function block diagram of the eye detecting device inaccordance with the third embodiment of the present invention.

FIG. 3B depicts a flow diagram of a method of detecting pupil inaccordance with the second exemplary embodiment of the presentdisclosure.

FIG. 4 depicts a flow diagram of a method of identifying iris inaccordance with the third exemplary embodiment of the presentdisclosure.

FIG. 5 depicts a flow diagram of a method of identifying iris inaccordance with the fourth exemplary embodiment of the presentdisclosure.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1A is a side view of the eye detecting device in accordance withthe first embodiment of the present invention. FIG. 1B is a front viewof the eye detecting device shown in FIG. 1A. FIG. 1C is a functionblock diagram of the eye detecting device in accordance with the firstembodiment of the present invention. Please refer to FIG. 1A to 1C, theeye detecting device 100 includes an optical assembly 110, an imagesensor 120, and an arithmetic unit 130. The optical assembly 110provides at least one incident light L1 to form at least one glint G1located near a pupil P1 of the eye E1. Specifically, the eye E1 has thepupil P1 and a periphery surrounding the pupil P1, and the glint G1 isformed on the periphery. The periphery includes an iris I1 and a sclera.The image sensor 120 is used to capture an eye image, and the eye E1image includes the glint G1 image. The arithmetic unit 130 analyzes agray scale value of the eye E1 image and obtains at least one positionof the glint G1 according to the gray scale value. Hence, the arithmeticunit 130 can determine the position of the pupil P1 of eye E1 accordingto the position of the glint G1.

The eye detecting device 100 can be disposed on the eyeglasses frame,and the eye detecting device 100 also can be disposed on the laptop orthe screen of the smartphone. In this embodiment, the eye detectingdevice 100 may be wearable, like eyeglasses. The optical assembly 110and the image sensor 120 are disposed on the supporting frame 150. Usercan wear the supporting frame 150, and the optical assembly 110 and theimage sensor 120 are in front of the user. However, in other embodiment,the eye detecting device 100 can be disposed on mobile device, forexample, laptop, the front camera lens or the screen of the smartphone.However, the present disclosure does not limit the disposition of theeye detecting device 100.

Practically, the supporting frame 150 can be an eyeglasses frame. Thesupporting frame 150 includes two rims 152 and two temples 154 connectedto rims 152 respectively. User can put the temples 154 on ears, and therims 152 are in front of the eye E1. However, the present disclosuredoes not limit the supporting frame 150.

The optical assembly 110 can emit at least one incident light L1entering the eye E1. The incident light L1 falls on the eye E1 to format least one glint by reflecting at the iris I1 of the eye E1. The glintis located near a pupil P1 of the eye E1. Specifically, the glint may beformed on the periphery surrounding the pupil P1, namely iris I1 orsclera. In this embodiment, providing one incident light L1 entering theeye E1 so that the number of the glint is one. It is worth to mentionthat the incident light L1 is the invisible light, such as infraredlight or near infrared light. The cornea covered on the iris I1 has asmooth surface so that the incident light L1 emitted in many directionscan form the glint G1 through the path between the cornea and the imagesensor 120.

Specifically, the optical assembly 110 includes at least one lightsource 112 and at least one dispersing component 114 so that the opticalassembly 110 provides at least one incident light L1. Practically, thelight source 112 can be light emitting diode (LED), and the dispersingcomponent 114 can guide light and has a plurality of opticalmicrostructures. The optical microstructures can be opticalmicrostructures, trenches or ribs. The trenches may be V-cut groovesWhen the light provided by the light source 112 is emitted into thedispersing component 114, the light can be reflected, refracted, orscattered by the optical microstructures so as to be transmitted from anoutgoing surface of the dispersing component 114.

The image sensor 120 is used to capture the eye E1 image. It is worth tomention that the wavelength range of the light captured by the imagesensor 120 covers the wavelength range of the incident light L1. The eyeE1 image appears in the eye region of user, for example, the eye whitearea (not shown), the iris I1 area, and the pupil P1 area. Besides, theeye E1 image shows the glint G1 image. Specifically, the image sensor120 senses the incident light L1 through photo-sensitive elements. Thephoto-sensitive elements can be complementary metal-oxide-semiconductorsensors (CMOS) or charge-coupled devices (CCD).

The arithmetic unit 130 can be a digital signal processor (DSP) or acentral processing unit (CPU). The arithmetic unit 130 analyzes a grayscale value of the eye image and obtains the distribution of the glintG1 through the gray scale value. The arithmetic unit 130 determines theposition of the pupil P1 of eye E1 according to at least onedistribution of the glint G1.

FIG. 1D depicts a flow diagram of a method of detecting pupil inaccordance with the first exemplary embodiment of the presentdisclosure. Please refer to FIG. 1B, FIG. 1C and FIG. 1D.

Implementing the step S101, when the user uses the eye detecting device100, such as the user wearing the supporting frame 150 of the eyedetecting device 100, the optical assembly 110 provides one incidentlight L1 entering into the eye E1. The incident light L1 is located atthe eye E1 and reflects to form one glint G1 near the pupil P1, such asthe iris I1.

It is worth to notice that the position where the incident light L1enters the iris I1 near the pupil P1 can be adjusted by changing thearrangement of the light source 112 or the disposition of the lightsource 112 and the dispersing component 114. Namely, the position of theglint G1 can be changed by the emission position of the incident lightL1. Hence, the position of the glint G1 depends on the emission positionof the incident light L1.

Implementing the step S102, the image sensor 120 captures a first eyeimage by photographing the eye E1. The first eye image photographed byimage sensor 120 shows the image of the eye E1 region and the image ofthe said glint G1. Then, the image sensor 120 transmits the data of thefirst eye image to the arithmetic unit 130.

Implementing the step S103, the arithmetic unit 130 analyzes a grayscale value of the first eye image to obtain the distributions of theglint G1. The 8-bit color image, namely 256-grayscale image is used asan example. The grayscale value is quantified as 256 colors from thepure black, through gray to white, and the grayscale value ranges from 0to 255. It is worth to notice that the gray scale value of the glint G1is near to or equal to 255, whereas the gray scale value of the pupil P1is near to 0. The arithmetic unit 130 can obtain the arrangement, shapeand range of the pixels which is close to the maximum gray scale valuein all pixels through the gray scale value distribution of the first eyeimage. Further, the arithmetic unit 130 speculates the arrangement ofthe pixels corresponding to the arrangement of the glint G1 in the firstimage.

Implementing the step S104, the arithmetic unit 130 determines theposition of the pupil P1 according to the position of the glint G1.Specifically, the arithmetic unit 130 selects an appropriate thresholdgray scale value first. The gray scale value of the pupil P1 is lessthan the said threshold gray scale value, whereas the gray scale valueof the glint G1 in the first eye image is greater than the saidthreshold gray scale value.

After confirming the position of the glint G1, the arithmetic unit 130scans the survey area M1 near the arrangement of the glint G1 (shown inFIG. 1B), and analyzes the gray scale value distribution of the surveyarea M1. The arithmetic unit 130 determines the part of the survey areaM1, whose gray scale value is less than the threshold gray scale value.The survey area M1 can be defined by at least one glint G1. Thepositions of the glint G1 and the pupil P1 are in the survey area M1. Itis worth to mention that the position of the glint G1 can be at theboundary of the survey area M1 or in the survey area M1. User can setthe range of the survey area M1 according to the pupil P1 size throughthe arithmetic unit 130. The present disclosure does not limit the rangeof the survey area M1.

The arithmetic unit 130 determines an area from the survey area M1 to bea specific area, and the gray scale value of the specific area is lessthan the threshold gray scale value. Further, the arithmetic unit 130determines whether the shape of the specific area matches with the shapeof the pupil P1 to reduce the possibility of the misjudgment of thepupil P1 position. For instance, the arithmetic unit 130 selects twospecific areas satisfied by the condition that the gray scale value ofthe specific areas are less than the threshold gray scale value. Whenone specific area is rectangle, and the other specific area is circular,the arithmetic unit 130 then determines one of the circular specificareas, which is circular, matches with the shape of the pupil P1.Besides, in order to reduce the possibility of the misjudgment of thepupil P1 position more, user can set the range of the pupil P1 area inthe first image. The arithmetic unit 130 determines whether theproportion of the specific area is within the range of the pupil P1 toreduce the possibility of the misjudgment of the pupil P1 position more.

It is worth to mention that the arithmetic unit 130 can analyze the grayscale value distribution of the survey area M1 near the glint G1 in thefirst eye image so as to reduce searching scope of the pupil P1. Hence,the position of the pupil P1 can be found quickly. Therefore, comparedwith conventional technology, the arithmetic unit 130 does not analyzethe gray scale value distribution of whole first eye image for searchingfor the pupil P1.

FIG. 2A is a side view of the eye detecting device in accordance withthe second embodiment of the present invention. FIG. 2B is a functionblock diagram of the eye detecting device in accordance with the secondembodiment of the present invention. Please refer to FIGS. 2A and 2B.The structure of an eye detecting device 200 in accordance with secondexemplary embodiment is similar to the eye detecting device 100 inaccordance with first exemplary embodiment. For example, the eyedetecting device 100 and 200 include the image sensor 120. However,there are some differences between the eye detecting devices 100 and200. The following detailed description explains the difference betweenthe eye detecting devices 100 and 200, and the same features arebasically not described again.

The eye detecting device 200 in accordance with the second embodimentincludes an optical assembly 210, an image sensor 120, and an arithmeticunit 130. The optical assembly 210 provides a plurality of incidentlights L1 to form a plurality of glints G1 located near a pupil P1 ofthe eye E1. The image sensor 120 is used to capture an eye image, andthe eye image includes these glints G1 image. The arithmetic unit 130analyzes a gray scale value of the eye E1 image and obtains distributionof the glints G1 according to the gray scale value. Hence, thearithmetic unit 130 determines the position of the pupil P1 of eye E1according to the distribution of the glints G1.

The optical assembly 210 can emit a plurality of incident lights L1enter into the eye E1. The incident lights L1 fall on the eye E1 to forma plurality of glints by reflecting at an iris I1 of the eye E1, and atleast part of glints are located near a pupil P1 of the eye E1.

In this embodiment, the optical assembly 210 includes only one or lesslight source 212 and a dispersing component 214. The incident lights canbe formed by dividing at least one light through the optical assembly210. In other embodiment, the optical assembly 210 may include aplurality of light sources 212 and exclude any dispersing component 214.The present disclosure does not limit the number of the light source 212and the structure of dispersing component 214.

FIG. 2C depicts a flow diagram of a method of detecting pupil inaccordance with the second exemplary embodiment of the presentdisclosure. Please refer to FIG. 2A, FIG. 2B and FIG. 2C.

Implementing the step S201, when the user uses the eye detecting device200, the optical assembly 210 provides a plurality of incident lights L1enter the eye E1. The incident lights L1 reflect to form a plurality ofglints G1 near the pupil P1, such as the iris I1.

It is worth to notice that the positions of the glints G1 can be changedwith the emission positions of the incident lights L1. For instance,there are four emission positions of the incident lights L1approximately arranged in a rectangle, and the aspect ratio of therectangle is 2:1. Then, four glints G1 are formed and arranged in arectangle with the aspect ratio of 2:1.

Implementing the step S202, the image sensor 120 captures a first eyeimage by photographing the eye E1. The first eye image photographed byimage sensor 120 shows the image of the eye E1 region and the image ofthe said glints G1. Then, the image sensor 120 transmits the data of thefirst eye image to the arithmetic unit 130.

Implementing the step S203, the arithmetic unit 130 can obtain thearrangement, shape and range of the pixels which each have close to themaximum gray scale value through the gray scale value. Further, thearithmetic unit 130 speculates the arrangement of the pixelscorresponding to the arrangement of the glints G1 in the first image.

Implementing the step S204, the arithmetic unit 130 determines theposition of the pupil P1 according to the distributions of the glintsG1. Specifically, the arithmetic unit 130 selects an appropriatethreshold gray scale value first. The gray scale value of the glints G1in the first eye image are greater than the said threshold gray scalevalue. After confirming the arrangement of the glints G1, the arithmeticunit 130 scans the survey area M1 near the arrangement of the glints G1(shown in FIG. 2A), and analyzes the gray scale value distribution ofthe survey area M1.

It worth to mention that the survey area M1 can be defined by thoseglints G1. The survey area M1 contains the arrangement of the glints G1and the pupil P1, and can be equal to or slightly larger than the areasurrounded by the glints G1.

In the same way, in order to reduce the possibility of the misjudgmentof the pupil P1 position, after the specific area which has gray scalevalue less than the threshold gray scale value is determined by thearithmetic unit 130, the arithmetic unit 130 determines whether theshape of the specific area matches the shape of the pupil P1, and theproportion of the specific area is within the range of the pupil P1.

It is worth to mention that the arithmetic unit 130 can define the shapeor range of the survey area M1 through distribution of the glints G1 soas to reduce the seeking range. Hence, the position of the pupil P1 canbe searched quickly.

FIG. 3A is a function block diagram of the eye detecting device inaccordance with the third embodiment of the present invention. Thestructure of an eye detecting device 300 in accordance with thirdexemplary embodiment is similar to the eye detecting device 200 inaccordance with second exemplary embodiment. For example, the eyedetecting devices 300 and 200 each include the optical assembly 210 andthe image sensor 120. However, there are some differences between theeye detecting devices 100 and 200. The following detailed descriptionexplains the difference between the eye detecting device 100 and 200,and the same features are basically not described again.

The eye detecting device 300 in accordance with the third embodimentincludes an optical assembly 210, an image sensor 120, an arithmeticunit 230, and the control unit 340. The optical assembly 210 provides aplurality of incident lights L1 to form a plurality of glints G1 locatednear a pupil P1 of the eye E1. The control unit 340 controls the timingthat the incident lights are emitted into the eyes, namely, the controlunit 340 can control that the optical assembly 210 providing differentincident lights L1 into the eyes E1 at different timing separately. Theimage sensor 120 captures the eye images at different timing, and theeye images include the glint G1 a and glint G1 b image. Namely, Theglint G1 a and glint G1 b image appear in each eye images captured atdifferent timing. The arithmetic unit 230 analyzes a gray scale value ofthe eye images captured at different timing and obtains positions ofglint G1 a and glint G1 b according to the gray scale value. Hence, thearithmetic unit 230 determines the position of the pupil P1 of eye E1according to the position of glint G1 a and glint G1 b.

Specifically, the image sensor 120 is used to capture the eye images atdifferent timing, and each the eye image shows these glint G1 a andglint G1 b image. The arithmetic unit 230 analyzes gray scale value ofthe eye image captured at different timing, in addition, the arithmeticunit 230 commands the control unit 340 so that the control unit 340controls the timing that the optical assembly 210 provides the incidentlights L1.

FIG. 3B depicts a flow diagram of a method of detecting pupil inaccordance with the second exemplary embodiment of the presentdisclosure. Please refer to FIG. 3A and FIG. 3B.

Implementing the step S301, the control unit 340 controls the opticalassembly 210 provides a plurality of incident lights L1 at a firsttiming. The incident lights L1 enter into the iris I1 area near thepupil P1 and than reflect to form a plurality of first glints G1 a. Thearrangement of the first glints G1 a is corresponding to the emissionarrangement of the incident lights L1. It is worth to notice that theoptical assembly 210 includes a plurality of light sources withoutincluding any dispersing component.

Implementing the step S302, the image sensor 120 captures a first eyeimage by photographing the eye E1 at the first timing. The first eyeimage photographed by image sensor 120 at the first timing and shows theimage of the eye E1 region and the image of the said first glints G1 a.Then, the image sensor 120 transmits the data of the first eye image tothe arithmetic unit 230.

Implementing the step S303, the control unit 340 controls the opticalassembly 210 provides a plurality of incident lights L1 at a secondtiming. The incident lights L1 enters the iris I1 area near the pupil P1and reflect to form a plurality of second glints G1 b. The arrangementof the second glints G1 b is corresponding to the emission arrangementof the incident lights L1. It is worth to notice that the first timingis not equal to the second timing, and the arrangement of the firstglints G1 a formed at the first timing is not equal to the arrangementof the second glints G1 b formed at the second timing. Specifically,part of the light source 112 provides some incident lights L1 at thefirst timing, the other light source 112 provides some incident lightsL1 at the second timing.

For example, the amount of the light sources 112 is four, and the lightsources 112 are arranged approximately in the rectangular array. Theaspect ratio of said rectangular array is 2:1. The control unit 340controls the optical assembly 210 to provide two light sources 112arranged in diagonally opposite corners of the rectangular array at thefirst timing, and then the control unit 340 controls the opticalassembly 210 to provide the other light sources 112 arranged indiagonally opposite corners of the rectangular array at the secondtiming. The present disclosure does not limit the number and arrangementof the light sources 112 provided by the optical assembly 210 atdifferent timing. The present disclosure does not limit the emissionsequence of the light sources 112.

Implementing the step S304, the image sensor 120 captures a second eyeimage by photographing the eye E1 at the second timing. The second eyeimage photographed by image sensor 120 at the second timing and showsthe image of the eye E1 region and the image of the said first glints G1b. Then, the image sensor 120 transmits the data of the second eye imageto the arithmetic unit 230.

It is worth to notice that the aforementioned first timing is namely thetiming that the user started using the eye detecting device 300, and thesecond timing is the another timing different from the first timing. Thefirst eye image photographed by image sensor 120 at the first timing,and the second eye image photographed by image sensor 120 at the secondtiming.

Implementing the step S305, the arithmetic unit 230 analyzes a grayscale value distribution of the first eye image and the second eye imageto obtain the distributions of the first glints G1 a and the secondglints G1 b. Specifically, the arithmetic unit 230 can obtain thearrangement, shape and range of the pixels which is close to the maximumgray scale value in all pixels through the gray scale value distributionof the first eye image and the second eye image. Further, the arithmeticunit 130 speculates the arrangement of the pixels corresponding to thearrangement of the first glint G1 a in the first image and the secondglint G1 b in the second image.

Implementing the step S306, a difference image between the first imageand the second image is produced by image subtraction. In thisembodiment, the amount of the light sources 112 is four, and the firstglints G1 a in the first image are provided by two light sources 112arranged in diagonally opposite corners of the rectangular array, andthe second glints G1 b in the second image are provided by the otherlight sources 112 arranged in other diagonally opposite corners of therectangular array. The difference image is generated by subtracting thesecond image from the first image, and the difference gray scale valueof the difference image range from −255 to 255.

Since the arrangement of the first glints G1 a and the arrangement ofthe second glints G1 b do not overlap, the gray scale valuescorresponding to the arrangement of the first glint G1 a and the secondglint G1 b in the difference image between the first image and thesecond image are proximate to critical value. For example, in thedifference image, the gray scale value corresponding to the arrangementof the first glint G1 a is proximate to a maximum value, whereas thegray scale value corresponding to the arrangement of the second glintsG1 b is proximate to a minimum value (negative gray scale value).

Thus, in the difference image, the gray scale value corresponding to thearrangement of the first glint G1 a and the second glint G1 b show aspecial pattern. In this embodiment, the special pattern is defined bytwo brightest spots and two darkest spots. However, in the differenceimage, the difference image can be generated by subtracting the firstimage from the second image. Hence, the gray scale value correspondingto the arrangement of the second glint G1 b is proximate to a maximumvalue, whereas the gray scale value corresponding to the arrangement ofthe first glints G1 a is proximate to a minimum value and is not limitedto the examples provided herein.

In addition, the arrangement of the first glints G1 a and the secondglint G1 b can be further determined through the arithmetic unit 230.Specifically, in the process of determining the arrangement of the firstglints G1 a and the second glint G1 b through the arithmetic unit 230,the arithmetic unit 230 analyzes the arrangement, shape and range of thepixels which are close to the maximum (255) and minimum (−255) grayscale value in all pixels to speculate a possibility arrangement of thefirst glints G1 a and the second glint G1 b. Then, the arithmetic unit230 speculates whether the possibility arrangement of the first glintsG1 a and the second glint G1 b corresponding to the above-mentionedspecial pattern.

Since the control unit 340 controls the different incident lights L1 toemit into the different positions of the eye E1 at the different timing,the arrangement of the first glints G1 a and the second glint G1 b atthe different timing can be arranged. The arrangement of the firstglints G1 a and the second glint G1 b can be more confirmed through thegray scale value and the above-mentioned special pattern after imagesubtraction. Hence, the possibility of the misjudgments of the glints G1position can be more reduced.

Implementing the step S307, the arithmetic unit 230 determines theposition of the pupil P1 according to the arrangement of the firstglints G1 a and the second glints G1 b. Specifically, the arithmeticunit 230 selects an appropriate threshold gray scale value first. Thegray scale value of the pupil P1 is less than the said threshold grayscale value, whereas the gray scale values of the first glints G1 a andthe second glint G1 b in the difference image are greater than the saidthreshold gray scale value. The arithmetic unit 230 confirms thearrangement of the first glints G1 a and the second glint G1 b throughthe gray scale value. After confirming the arrangement of the firstglints G1 a and the second glint G1 b, the arithmetic unit 230 scans thesurvey area M1 near the arrangement of the first glints G1 a or thesecond glint G1 b, and analyzes the gray scale value distribution of thesurvey area M1. The arithmetic unit 230 determines the part of thesurvey area M1, whose gray scale value is less than the threshold grayscale value.

For example, the gray scale values corresponding to the arrangement ofthe first glint G1 a and the second glint G1 b in the difference imageare proximate to critical value, and the gray scale value correspondingto the arrangement of the first glint G1 a is proximate to a maximumvalue, whereas the gray scale value corresponding to the arrangement ofthe second glints G1 b is proximate to a minimum value. Thus, thearithmetic unit 230 confirms the arrangement of the first glints G1 athrough the gray scale value, and then scans the survey area M1 near thearrangement of the first glint G1 a to determines the position of thepupil P1.

In particular, the survey area M1 can be defined by these first glintsG1 a and/or second glints G1 b. The range of the survey area M1 containsthe arrangement of the first glints G1 a and/or second glints G1 b, andcan be equal to or slightly larger than the area surrounded by thearrangement of the first glints G1 a and/or second glints G1 b.Specifically, the position of the first glints G1 a and/or second glintsG1 b can be at the boundary of the survey area M1 or in the survey areaM1. User can set the range of the survey area M1 according to the pupilP1 size through the arithmetic unit 230. The present disclosure is notlimited to the range of the survey area M1.

The arithmetic unit 230 selects the specific area from the survey area,and the gray scale value of the specific area is less than the thresholdgray scale value, and then determines whether the shape and proportionof the specific area matches the pupil P1 in the difference image toreduce the possibility of the misjudgment of the pupil P1 position.

The arithmetic unit 230 can analyze the gray scale value distribution ofthe survey area M1 near the arrangement of the first glints G1 a and/orsecond glints G1 b in the difference image so as to search the positionof the pupil P1 quickly. Therefore, compared with conventionaltechnology, the arithmetic unit 230 does not analyze the gray scalevalue distribution of whole first or second eye image for searchingscope of the pupil P1.

FIG. 4 depicts a flow diagram of a method of identifying iris inaccordance with the third exemplary embodiment of the presentdisclosure. The method of identifying iris in accordance with the thirdexemplary embodiment can be implemented through eye detecting device 200(shown in FIG. 2A). Please refer to FIG. 2A and FIG. 4.

Implementing the step S401, when the eye E1 is located at a referenceposition, and the reference position is corresponding to a positionwhere the eye gazes straight ahead in this embodiment. the opticalassembly 210 provides a plurality of incident lights L1 entering the eyeE1. The incident lights L1 reflect to form a plurality of glints G1 nearthe pupil P1, and the arrangement of those glints G1 is defined to afirst reference point, a second reference point and a third referencepoint.

Specifically, the incident lights L1 can be provided by the light source212 and the dispersing component 214 so that the emission positions ofthe incident lights L1 are the illuminated position of the dispersingcomponent 214. Or, the incident lights L1 can be provided by at leastthree light sources 212 without any dispersing component 214 so that theemission positions of the incident lights L1 are the position where thelight sources 212 are placed. The position that the incident lights L1enter in the iris I1 area near the pupil P1 can be adjusted by adjustingthe arrangement of the light source 212 or the disposition of the lightsources 212 and the dispersing component 214.

The first reference point, the second reference point and the thirdreference point are located near a pupil P1 of the eye E1 as a mark forlocating the eye E1 at the reference position. The positions of thefirst reference point, the second reference point and the thirdreference point are corresponding to the emission position of theincident lights L1. In this embodiment, when the user looks straightahead, namely, the eye gazes straight ahead, the user presets thoseglints positions corresponding to the emission arrangement of theincident lights L1 to be regarded as the positions of the firstreference point, the second reference point and the third referencepoint. Specifically, a first reference axis is formed between the firstreference point and the second reference point. A second reference axisis formed between the second reference point and the third referencepoint. A reference angle is formed between the first reference axis andthe second reference axis. Besides, in order to mark the referenceposition clearly, the method of identifying iris can further includepresets the fourth reference point or more other reference point, butnot limited to the examples provided herein.

In this embodiment, three emission positions of the incident lights L1are provided and are arranged approximately as the right angledtriangle. The ratio of two sides of said right angled triangle is 2:1.Hence, those glints are located near a pupil P1 of the eye E1 andarranged approximately as the right angled triangle. Namely, the ratiobetween the first reference axis and the second reference axis is 2:1,and the reference angle is approximate to 90 degrees.

Implementing the step S402, when the eye E1 moves from the referenceposition to a measuring position, the incident lights L1 form a firstmeasuring glint, a second measuring glint, and a third measuring glintnear a pupil P1 of the eye E1. A first axis is formed between the firstmeasuring glint and the second measuring glint. A second axis is formedbetween the second measuring glint and the third measuring glint. Anangle is formed between the first axis and the second axis.

Specifically, the eye E1 is substantially spherical, and the iris I1 isthe portion rising slightly above the surface of the sphere. Thearrangement of those glints G1 is changed while the eye E1 movescorresponding to the reference position, whereas the glints G1 are thefirst reference point, the second reference point and the thirdreference point. Namely, when the eye E1 gaze direction moves from thefront direction to lateral direction, the arrangement of those glints G1is changed from the first reference point, the second reference pointand the third reference point to the first measuring glint, the secondmeasuring glint, and the third measuring glint.

Implementing the step S403, the image sensor 120 captures an eye imageby photographing the eye E1. The eye image photographed by image sensor120 shows the image of the eye E1 region and the image of the said firstmeasuring glint, the second measuring glint, and the third measuringglint. Then, the image sensor 120 transmits the data of the eye image tothe arithmetic unit 130 or 230.

Implementing the step S404, the arithmetic unit 130 or 230 analyzes agray scale value distribution of the eye image to obtain the arrangementof the first measuring glint, the second measuring, and the thirdmeasuring glint. Specifically, the arithmetic unit 130 or 230 can obtainthe arrangement, shape and range of the pixels which is close to themaximum gray scale value (255) in all pixels through the gray scalevalue distribution of the eye image. Further, the arithmetic unit 130 or230 speculates the arrangement of the pixels corresponding to thearrangement of the first measuring glint, the second measuring, and thethird measuring glint in the image.

Implementing the step S405, the displacement amounts of the firstmeasuring glint, the second measuring glint, and the third measuringglint relative to the first reference point, the second reference pointand the third reference point are calculated respectively. Therefore, adeformation amount caused by the iris image of the eye at the measuringposition relative to the iris image of the eye at the reference positionis obtained. Specifically, the arithmetic unit 130 or 230 calculates thefirst variation, which is a length and angular variation of the firstaxis relatives to the first reference axis. The arithmetic unit 130 or230 calculates the second variation, which is a length and angularvariation of the second axis relatives to the second reference axis.Equally, the third variation which is an angular variation of the anglerelatives to the reference angle is calculated. Hence, the arithmeticunit 130 or 230 calculates the iris image deformation amount accordingto the first variation, the second variation, and the third variation.Furthermore, the proportion of the iris image deformation amount can beestimated according to the relative proportion of the first axisrelatives to the first reference axis and the relative proportion of thesecond axis relatives to the second reference axis. Besides, thedistance between the image sensor 120 and eye E1 can be estimatedaccording to the length of the first axis and the second axis. Hence,the size of the pupil P1 can be estimated so that the position of thepupil P1 can be searched quickly.

It is worth to notice that when the user looks straight ahead, the shapeof the pupil P1 image photographed by image sensor 120 is similar to acircle. While the measuring position is equal to the reference position,namely, the user keeps looking straight ahead, the shape of the pupil P1image photographed by image sensor 120 keeps being similar to circle.While the measuring position is not equal to the reference position,namely, the eye E1 gaze direction moves from the front direction tolateral direction, the shape of the pupil P1 image photographed by imagesensor 120 is similar to an ellipse.

The arithmetic unit 130 or 230 can calculate the major axis and minoraxis of the said ellipse according to the first variation, the secondvariation, and the third variation. Hence, the boundary of the pupil P1can be estimated so that the boundary of the pupil P1 can be searchedquickly.

FIG. 5 depicts a flow diagram of a method of identifying iris inaccordance with the fourth exemplary embodiment of the presentdisclosure. Please refer to FIG. 5 and FIG. 2A. The method ofidentifying iris shown in FIG. 5 is similar to the method of identifyingiris shown in FIG. 4. The differences between these methods ofidentifying iris s are further discloses as follows.

Implementing the step S501, in this embodiment, the optical assembly 210provides a plurality of incident lights L1 entering the eye E1. Theincident lights L1 reflect to form a plurality of glints G1 near thepupil P1. Specifically, the incident lights L1 can be provided by thelight source 212 and the dispersing component 214 so that the emissionpositions of the incident lights L1 are the illuminated position of thedispersing component 214. Or, the incident lights L1 can be provided byat least three light sources 212 without any dispersing component 214 sothat the emission positions of the incident lights L1 are the positionwhere the light sources 212 are placed. The position that the incidentlights L1 enter in the iris I1 area near the pupil P1 can be adjusted byadjusting the arrangement of the light source 212 or the disposition ofthe light sources 212 and the dispersing component 214.

Implementing the step S502, the user sets a first reference point, asecond reference point and a third reference point as a mark forlocating the eye E1 at the reference position. The positions of thefirst reference point, the second reference point and the thirdreference point are corresponding to the emission position of theincident lights L1. In this embodiment, when the user looks straightahead and there is a reference distance between the optical assembly 210and the eye E1, the user presets those glints positions corresponding tothe emission arrangement of the incident lights L1 to be regarded as thepositions of the first reference point, the second reference point andthe third reference point. However, the reference position cannot be theposition right front the eye E1 when the eye E1 gaze direction deviatesfrom the front direction of the eye E1, and is not limited to theexamples provided herein.

Specifically, a first reference axis is formed between the firstreference point and the second reference point. A second reference axisis formed between the second reference point and the third referencepoint. A reference angle is formed between the first reference axis andthe second reference axis. In addition, in order to mark the referenceposition clearly, the method of identifying iris can further includepresets the fourth reference point or more other reference point, butnot limited to the examples provided herein.

In this embodiment, three emission positions of the incident lights L1are provided and are arranged approximately as the right angledtriangle. The ratio of two sides of said right angled triangle is 2:1.Hence, those glints are located near a pupil P1 of the eye E1 andarranged approximately as the right angled triangle. Namely, the ratiobetween the first reference axis and the second reference axis is 2:1,and the reference angle is approximate to 90 degrees. It is worth tonote that the user presets those glints positions corresponding to theemission arrangement of the incident lights L1 to be regarded as thepositions of the first reference point, the second reference point andthe third reference point while there exists the reference distancebetween the optical assembly 210 and the eye E1.

Implementing the step S503, when the eye E1 is located at a measuringposition, there is a measuring distance between the optical assembly 210and the eye E1. The incident lights L1 form a first measuring glint, asecond measuring glint, and a third measuring glint near a pupil P1 ofthe eye E1. The positions of the first measuring glint, the secondmeasuring glint, and the third measuring glint are corresponding to thepositions of the first reference point, the second reference point andthe third reference point. A first axis is formed between the firstmeasuring glint and the second measuring glint. A second axis is formedbetween the second measuring glint and the third measuring glint. Anangle is formed between the first axis and the second axis.

Specifically, since different user has different face and nose height,there exists different distance between the optical assembly 210 and theeye E1 while different user wear eye detecting device 200 or 300. Hence,the glint G1 position formed by emitting the incident light L1 into theeye E1 can be changed to the first, second and the third measuringglint. That is, when the eye gaze direction remains without moving, theglint G1 position formed by emitting the incident light L1 into the eyeE1 can be changed proportionally from the aforementioned the first,second and third reference point to the first, second and the thirdmeasuring glint. The angle is equal to the reference angle.

In this embodiment, since the ratio between the first and secondreference axis is 2:1, the ratio between the first and second axis is2:1. Since the reference angle is approximate to 90 degrees, the angleis approximate to 90 degrees.

Implementing the step S504, the image sensor 120 captures an eye imageby photographing the eye E1. The eye image photographed by image sensor120 shows the image of the eye E1 region and the image of the saidfirst, second, and the third measuring glint, and an iris I1 image.Then, the image sensor 120 transmits the data of the eye image to thearithmetic unit 130 or 230.

Implementing the step S505, the arithmetic unit 130 or 230 analyzes agray scale value distribution of the eye image to obtain the arrangementof the first, second, and third measuring glint. Specifically, thearithmetic unit 130 or 230 can obtain the arrangement, shape and rangeof the pixels which each have close to the maximum gray scale value(255) through the gray scale value distribution of the eye image.Further, the arithmetic unit 130 or 230 speculates the arrangement ofthe pixels corresponding to the arrangement of the first, second, andthird measuring glint in the image.

Implementing the step S506, the variation of the distance between thefirst measuring glint and the second measuring glint with respect to thedistance between the first reference point and the second referencepoint is calculated. The variation of the distance between the secondmeasuring glint and the third measuring glint with respect to thedistance between the second reference point and the third referencepoint is calculated. Accordingly, the resolution variation of an irisimage when the eye is located at the measuring position is obtained.Specifically, the arithmetic unit 130 or 230 calculates the firstvariation, which is a length variation of the first axis relatives tothe first reference axis. The arithmetic unit 130 or 230 calculates thesecond variation, which is a length variation of the second axisrelatives to the second reference axis. Hence, the arithmetic unit 130or 230 calculates the resolution variation of an iris image according tothe first and second variation.

For example, the first reference axis has 20 pixels, whereas the secondreference axis has 10 pixels. The ratio between pixel of the first andsecond reference axis is 2:1. The arithmetic unit 130 or 230 calculatesthat the first axis has 10 pixels and the second axis has 5 pixels.Hence, the arithmetic unit 130 or 230 calculates that the first axis isdecrease by two times compare to the first reference axis and the secondaxis is decrease by two times compare to the second reference axis.Namely, the first and second variation is two. Hence, the boundary ofthe pupil P1 can be estimated so that the boundary of the pupil P1 canbe searched quickly.

In summary, the present disclosure provides eye detecting device,methods of detecting pupil and identifying iris. The eye detectingdevice includes an optical assembly, an image sensor, and an arithmeticunit. The arithmetic unit can analyze the gray scale value distributionof the survey area near the arrangement of the glint in the first eyeimage so as to reduce searching scope of the pupil. Hence, the positionof the pupil can be searched quickly. Therefore, compared withconventional technology, the arithmetic unit does not analyze the grayscale value distribution of whole first eye image for searching scope ofthe pupil.

The present disclosure provides eye detecting device, methods ofdetecting pupil. The eye detecting device includes an optical assembly,an image sensor, an arithmetic unit, and the control unit. Since thecontrol unit controls the different incident lights to emit into thedifferent positions of the eye at the different timing, the arrangementof the first and second glint at the different timing can be arranged.The arrangement of the first and second glint can be more confirmedthrough the gray scale value and the special pattern after imagesubtraction. Hence, the possibility of the misjudgments of the glintsposition can be more reduced. The arithmetic unit can analyze the grayscale value distribution of the survey area near the arrangement of thefirst glints and/or second glints in the difference image so as tosearch the position of the pupil quickly. Therefore, compared withconventional technology, the arithmetic unit does not analyze the grayscale value distribution of whole first or second eye image forsearching scope of the pupil.

The arithmetic unit can calculate the major axis and minor axis of thesaid ellipse according to the first variation, the second variation, andthe third variation. Hence, the boundary of the pupil P1 can beestimated so that the boundary of the pupil P1 can be searched quickly.

The present disclosure provides methods of identifying iris. Thearithmetic unit can calculate the major axis and minor axis of the saidellipse according to the first, second, and third variation. Hence, theboundary of the pupil can be estimated so that the boundary of the pupilcan be searched quickly.

The present disclosure provides methods of identifying iris. Thearithmetic unit can calculate the first, second, and third variation.Hence, the boundary of the pupil can be estimated so that the boundaryof the pupil can be searched quickly.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present disclosure, without any intention to limit thescope of the present disclosure thereto. Various equivalent changes,alternations or modifications based on the claims of present disclosureare all consequently viewed as being embraced by the scope of thepresent disclosure.

What is claimed is:
 1. A method of identifying iris comprising:providing, by an optical assembly, a plurality of different incidentbeams entering an eye, the eye locating at a reference position, whereinthe optical assembly includes only one single light source and only onelight dispersing component, and the only single light source isconfigured to generate light entering into the only one light dispersingcomponent so that the light is divided into the plurality of incidentbeams entering the eye by the light dispersing component; setting afirst reference point, a second reference point and a third referencepoint as a mark for locating the eye at the reference position, whereinpositions of the first reference point, the second reference point andthe third reference point are corresponding to emission positions of theincident beams; forming a first measuring glint, a second measuringglint, and a third measuring glint near a pupil of the eye by theincident beams after the eye moves from the reference position to ameasuring position, and a plurality of positions of the first measuringglint, the second measuring glint, and the third measuring glint arecorresponding to the positions of the first reference point, the secondreference point and the third reference point; capturing an eye image ofthe eye including a first measuring glint image, a second measuringglint image, a third measuring glint image, and an iris image; analyzinga gray scale value of the eye image by comparing the gray scale valuewith a threshold gray scale value through an arithmetic unit to obtainthe positions of the first measuring glint, the second measuring glint,and the third measuring glint; and calculating a first variation of afirst line defined by the first measuring glint and the second measuringglint with respect to a first reference line defined by the firstreference point and the second reference point, and calculating a secondvariation of a second line defined by the second measuring glint and thethird measuring glint with respect to a second reference line defined bythe second reference point and the third reference point, so as toobtain an resolution variation of the iris image when the eye is locatedat the measuring position.
 2. The method of identifying iris accordingto claim 1, wherein the reference position is corresponding to aposition where the eye gazes straight ahead.
 3. The method ofidentifying iris according to claim 1, wherein the incident beams areinfrared lights.
 4. The method of identifying iris according to claim 1,wherein the eye image is captured by an image sensor.
 5. The method ofidentifying iris according to claim 1, wherein the dispersing componenthas a plurality of optical microstructures to divide the light into theincident beams.
 6. The method of identifying iris according to claim 1,further comprising: calculating a deformation amount of the iris imageat the measuring position relative to the iris image at the referenceposition according to the first variation.
 7. A method of identifyingiris comprising: providing, by an optical assembly, a plurality ofincident beams and forming a plurality of glints reflected by theincident beams; setting a first reference point, a second referencepoint and a third reference point as a mark for locating the eye at areference position; forming a first measuring glint, a second measuringglint, and a third measuring glint near a pupil of the eye by theincident beams after the eye moves from the reference position to ameasuring position; capturing an eye image of the eye including a firstmeasuring glint image, a second measuring glint image, a third measuringglint image, and an iris image; analyzing a gray scale value of the eyeimage by comparing the gray scale value with a threshold gray scalevalue through an arithmetic unit to obtain the positions of the firstmeasuring glint, the second measuring glint, and the third measuringglint; calculating a first variation of a first line defined by thefirst measuring glint and the second measuring glint with respect to afirst reference line defined by the first reference point and the secondreference point, and calculating a second variation of a second linedefined by the second measuring glint and the third measuring glint withrespect to a second reference line defined by the second reference pointand the third reference point; and calculating an iris image deformationamount according to the first variation, the second variation and thethird variation; wherein the iris image deformation amount is caused bythe iris image of the eye at the measuring position relative to the irisimage of the eye at the reference position.